Details component lacks styling

[matttomas]

The gov.uk design system 'details' component seems to lack styling when used with the tech docs template. I have attached an image showing the difference

.

[jamescarr28]

Is fixed by

• [ Add option to use GOV.UK Design System components #443 ] and
• [ Bump govuk-frontend from 5.11.0 to 6.1.0 #449 ]